采用红外光谱实验结合氢氟酸化学处理方法深入研究景德镇地区高岭石结构特征。通过解析红外光谱图确定该区高岭石为无序高岭石范畴,其结构中含有似地开石结构BCBCBC的八面体空位取代。通过对比氢氟酸处理前后的红外图谱,分析出该地区高岭土不含有地开石和珍珠石这两种多型。实验表明红外光谱分析对高岭土中存在的次要矿物伊利石不灵敏,而利用氢氟酸处理可以有效地鉴别,因而提出了一种利用红外光谱鉴定高岭石-伊利石混合物相的新方法。
Kaolinite is an important kind of ceramic and chemical raw material, with its name derived from the Gaoling Mountain of Jingdezhen area in Jiangxi Province. The physical and chemical properties of kaolinite can be affected by the changes of the stacking structure and crystal defects between its unit layers. These variations in structure can be sensitively reflected in Infrared (IR) spectroscopy, and the high frequency range of IR, in particular, can be effectively used to analyze the OH stretching vibration in kaolinite. The sample studied was collected from the Gaoling deposit in the middle of Ehugranite, east of Jingdezhen. The residual kaolin was derived from the hydrolysis and weathering of granite and pegmatite in a hot and humid environment.The structural characteristics of kaolinite from the Gaoling deposit were studied by means of hydrofluoric acid (HF) treatment and infrared (IR) spectroscopy analysis. According to the Stockes' Law, the authors concentrated the frictions of kaolin in 〈4 μm, and mixed 200 mg of them with 16 mL and 8 mL hydrofluoric acid (12 mol/L) for 5 minutes, respectively. The residual clay JDZ-8HF-1 and JDZ-8HF-2 were studied by IR.In view of the very weak bands ν2 and ν3 of the IR spectrum in the high frequency range of the untreated sample JDZ-8HF(〈4 μm), the authors hold that kaolinite from this area is in the range of disorder. This disorder is mainly caused by the decreasing of the angle between c* axis and O—H axis within the kaolinite crystal and the increasing of the interlayer cohesive energy. Based on analyzing the characteristics of four bands in the high frequency range, the authors also consider that the structure of kaolinite has a dickite_like displacement of BCBCBC octahedral vacancy. From the low IR frequency range of JDZ-8HF (〈4 μm), the characteristic peaks of kao- linite and quartz could be identified, but other phases within the sample could not be found. After 16 mL (12 mol/L) HF treatment, the IR spectrum of JDZ-8HF-1